Practice performing the Chi-Squared test with the problems below. We collected data by flipping a two-sided coin 200 times. The coin landed heads-up 108 times and tails-up 92 times. Perform a Chi-Square test to see if there is any statistical difference between our results and the expected results. Accept or reject the null hypothesis.
Null hypothesis: There is no statistical difference between the number of heads and the number of tails. Outcomes Observed Expected O-E (O-E)2 (O-E)2/E
Outcome Outcome
X Chi Square Value:
Degrees of Freedom:.
Accept or Reject Null Hypothesis:.

Hello there!

we know that she earns $8 in the job 1 and $12 in the job 2; let's call J1 the amount of hours worked in the job 1, and J2 the number of hours worked in the job 2, then we have the system of equations:

J1 + J2 = 30

J1*$8 + J2*$12 = $268

We can isolate J1 in the first equation and obtain:

J1 = 30 - j2, and now we can replace this in the second equation and obtain the value of j2:

J1*$8 + J2*$12 = $268

(30 - J2)*$8 + J2*$12 = $268

$240 +$4*J2 =$268

J2 = ($268 - $240)/$4 = 28/4 = 7 hours

She worked 7 hours in the job 2

you can replace it in the first equation and get:

7 + J1 = 30

J1 = 30 - 7 = 23 hours

she worked 23 hours in the job 1.